People who study infectious diseases and who work in public health have long known a bad pandemic would one day come.

They knew such an event would overwhelm hospitals, strain supply chains, and place stresses on society that we would be ill-equipped to meet. Countries like the United States have for decades prepared to respond to such a crisis.

But despite all the planning, the Covid-19 pandemic has, in myriad ways, not played out as expected. Three years after the first reports of a novel virus emerged from China, these experts admit that the microbe and the world’s response to it have continuously deviated from their forecasts.

In the hope that important lessons for next time can be found in the things we didn’t anticipate this time, STAT asked 23 experts what had surprised them the most about the pandemic.

Containment can buy time

Ben Cowling, head of the division of epidemiology and biostatistics at the Hong Kong University School of Public Health, was working with the World Health Organization in 2019 to revise its response plan for pandemic influenza. He and his co-authors wrote that countries should focus their efforts on trying to mitigate the impact of a
pandemic rather than trying to stop it.

“What we’d written on page 1 of these flu pandemic guidelines is: Containment is futile. Don’t waste too much time on containment,” Cowling said.

The report listed about 20 non-pharmaceutical measures countries could try, things like closing schools and urging people to wear masks. “We didn’t consider a shelter- in-place [order] — that wasn’t on the list,” he said. “We just couldn’t envisage something like that being considered. And then, of course, that was the go-to measure for many countries in March and April of 2020.” 

After China successfully slowed the spread of the new virus with draconian measures limiting individuals’ movements, many countries instituted some versions of what came to be known as “lockdown.” In some cases the actions were too late or too inefficiently implemented to make a big difference. But a number of countries deployed these measures with significant success; New Zealand, Australia, Singapore, South Korea, and Japan, among others, lost far fewer lives than peer nations. And of course China, where the pandemic began, kept Covid largely at bay until very recently, albeit with restrictions that would not be accepted in other parts of the world.

The WHO pandemic flu response plan is being updated to incorporate what was learned about containment efforts during Covid. Cowling said it won’t advise long-term efforts to try to stop a new pandemic virus, but “temporary containment to buy time, actually, I think some places will consider.”

The quiet
When countries around the world started following China’s lead and imposing social distancing measures — some very strict, others less so — the impact was eerie. City streets that were normally traffic-clogged became vast open spaces. Office towers sat empty. Shops and restaurants were closed, in some cases boarded up.

It is not an exaggeration to say it was unlike any time anyone alive today had ever experienced.

“The sheer quiet was just striking,” said Maria Van Kerkhove, the WHO’s lead on the pandemic. “I was in several different cities in China in February 2020 and the silence. … No one on the streets. Blue skies, because there were no cars on the road. You saw pictures from around the world of the air cleaning up in India, in Paris.”

The baking bonanza
People who had spent any time thinking about pandemics anticipated and prepared for the Great Toilet Paper Shortage of spring 2020.

But some of the other shortages that occurred caught even people steeped in pandemic preparedness by surprise. Flour. Butter. Yeast. Eggs. Who could have predicted pent-up people would turn their attention, en masse, to trying to perfect sourdough bread? Certainly not Nancy Messonnier, then director of the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention. Messonnier was the official who warned Americans in late February 2020 about what was barreling towards them — and promptly got silenced by the Trump administration for her candor.

She had already purchased supplies of bottled water, toilet paper, and bread by the time Atlanta schools were closing and society in general finally grasped a life-altering event was unfolding. Still, on the day her kids’ school closed, Messonnier headed to her local grocery store. It was chockablock with people hunting for the stuff she’d already stocked up on. She was searching for ingredients for cookies.

“I just figured I’d be home and I’d have time to bake,” she said.

Later others had the same idea. For weeks that spring, flour, yeast, and other baking essentials were as rare as hen’s teeth.

How variable the illness was
Covid has killed millions around the world, including more than 1 million in the United States. But some people who have been infected have no symptoms at all. Others have the equivalent of a head cold.

Some patterns are intuitive. Many of the deaths have been in people in their 70s, 80s, and beyond. Many have been in people with chronic health conditions that undermine their ability to fight off the infection.

But sometimes the variability of the illness makes little sense, a fact that has surprised Deepta Bhattacharya, professor of immunology at the University of Arizona College of Medicine.

“For instance, my dad and my sister both got it in May. My dad barely knew. He has asthma, and so he just thought it was just his asthma flaring up,” he said. “My sister had a much rougher go of it. She had a pretty bad cough that lasted over a month.”

“And they had the same vaccine history. They both had had three shots at the time that they got it.”

How quickly people could be reinfected
While an ever-dwindling number of people have not yet experienced a Covid infection, some have been infected several times. For some, the interval between Covid bouts is amazingly short.

“Anecdotally, I know several instances where infections occurred, the infection resolved clinically, and then the person became symptomatic again with SARS-CoV-2 positivity a few weeks after the initial infection,” said Stanley Perlman, a longtime coronavirus researcher at the University of Iowa.

Human coronaviruses, which cause colds, don’t trigger long-term immunity after infection. But studies suggest reinfection occurs on average about a year after a previous infection; one study suggests the interval is much longer. So how do we make sense of intervals of mere weeks?

Perlman doesn’t know, though he notes it’s not clear if these are reinfections or relapses, because the viruses from the sequential infections were not isolated and compared.